Abstract: This paper analyzes the present applications of low voltage bus protection,and presents a new solution of simplified bus protection.Based on the characteristics of low voltage bus topology,the bus unit module is abstracted.Each bus unit module calculates the overcurrent condition of its incoming line and bus section by using the overcurrent of the other bus unit modules.By referring to the blocking signals from the outgoing line protection,selective tripping of weak power,incoming line or bus section is realized and fast fault clearing achieved.